Enrichment of a local sourdough bread with zinc and selenium through the use of biofortified whole wheat flour

Abstract

SummaryIn this study, obtaining sourdough bread enriched in zinc (Zn) and selenium (Se) with biofortified whole wheat flour (BWWF) was investigated. Sourdough bread flour was blended with BWWF in the ratios of 25:75, 50:50 and 75:25. The Zn and Se contents varied from 12.06 to 43.06 mg/kg and from 80.73 to 267.58 μg/kg in the substituted flours (SFs), respectively. Gluten‐quality‐related technological and rheological properties of SFs were also determined. The BWWF negatively affected those parameters, and GlutoPeak torque before maximum and peak maximum time, alveograph energy and extensibility, sedimentation volume, gluten index and lactic acid solvent retention capacity values decreased substantially to 21.0 GPU, 27.5 s, 85.67 10−4 × J, 18.0 mm, 33.33 mL, 81.98% and 78.72%, respectively. The Zn contents of the SFs bread varied between 10.48 and 43.88 mg/kg, and the Se contents were found between 55.7 and 224.3 μg/kg. At 75% replacement, the recommended daily allowance (RDA) was obtained at 33.3% and 36.0% for selenium in adults, respectively, while it was 27.1% for zinc and 25.6% for selenium at the 50% substitution level. With the increase in substitution rates, the volumes of the SFs breads decreased from 337.5 to 516.3 mL, their organoleptic properties deteriorated, and the hardness of the breads increased from 507.5 to 3633.1 g. In the study, the whiteness index (WI) value was higher in the A yeast combination breads. The sensory properties of pore structure, taste and chewiness of the 25% substitution SFs bread were close to those of the control. Compared with control bread, all SFs bread had statistically higher (P < 0.01) ash, protein, total phenolic contents and antioxidant activity (ranging from 1.893% to 2.495%, 8.22% to 11.60%, 75.85 to 117.74 mg GAE/100 g and 8.84 to 13.34 inhibition%, respectively).